Wireless fluid shut-off valve

ABSTRACT

A low-cost safety valve for gas lines and similar supply lines that can be remotely activated via a secure wireless link employing a low leakage sealing mechanism that is compatible with low energy actuators to for extended battery life. A miniaturized controller and wireless electronics assembly provides the control mechanism for actuating the valve, as well as reporting data regarding the valve status to wireless interrogators or external networks via an ad hoc wireless network. A variety of simple magnetic valve operating mechanisms can be implemented with the miniaturized electronic control circuits and the valve body. Such control actuation mechanisms enable automatic resetting or manual resetting valves. The gas line shut off valve can provide important safety benefits at an affordable price.

RELATED APPLICATIONS

This application claims the benefit of priority to U.S. ProvisionalApplication No. 61/263,355, entitled “Low Cost Wireless Gas Meter andShut-Off Valve Using Wireless Sensor Network Technology With A MagneticMonitoring and Resetting Mechanism” filed Nov. 21, 2009, the entirecontents of which are hereby incorporated by reference.

BACKGROUND

Residential and industrial use of natural gas and other flammable gassesprovide many economic and quality of life benefits, but at a cost interms of safety and infrastructure. Due to the flammable and explosivenature of natural gas, shutoff valves are needed in order to limit thesupply of gas to a structure in the event of fire, structural damage(e.g., from earthquakes), and gas leaks, as well as when a structure isno longer occupied. Manually operated valves are currently used forisolating gas supplies to structures. However, such battles require gasutility workers to enter the structure in order to close the valve whenneeded. In the event of a fire emergency or significant structuraldamage, such manual actuation of the valves can represent a significantrisk to workers. Further, fire and rescue personnel may be held up inthe air response to emergency by the need to wait for someone from thegas utility to arrive on scene to close the gas isolation valves.

SUMMARY

The various embodiments provide remotely actuatable fluid isolationvalves and methods for remotely shutting fluid isolation valvesutilizing wireless communication networks. The embodiments provide alow-cost shutoff valve for a gas, water, and other fluid supply linesthat can be remotely activated via a wireless communication networkwhich may be multi-point or point-to-point, self forming and adaptive. Asimple closure valve provides low leakage sealing using a mechanism thatis compatible with low energy actuators to enable long lifebattery-operated control circuits. The valve can be configured to betamper proof and failsafe. Miniaturized controller and wireless networkelectronics provides a control mechanism for actuating the valve, aswell as reporting data regarding the valve status to external networksvia a wireless ad hoc communication network. A variety of simplemagnetic valve operating mechanisms can be implemented with theminiaturized electronic control circuits and the valve body. Suchcontrol actuation mechanisms enable self resetting or manual resettingvalves. When implemented on gas lines, the embodiment shutoff valves canprovide important safety benefits at an affordable price. Theprogrammable control processors and wireless transceivers of the variousembodiments enable useful capabilities including, for example,collection and communication of data from a variety of sensors,automatic actuation (i.e., closure) in response to sensor data (e.g.,elevated temperature), aggregate behavior (e.g., automatic actuation bya group of valves in response to collective analysis of sensor data frommultiple valves), and relative location estimation based upon relativesignal strength of wireless signals, with these capabilitiesprogrammable and updatable “over the air” via the ad hoc wirelesscommunication networks.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and constitutepart of this specification, illustrate exemplary embodiments of theinvention, and together with the general description given above and thedetailed description given below, serve to explain the features of theinvention.

FIG. 1 is a top view of a wireless gas shutoff valve according to anembodiment.

FIG. 2 is an exploded view of the wireless gas shutoff valve embodimentshown in FIG. 1.

FIG. 3 is a perspective view of the wireless gas shutoff valveembodiment shown in FIG. 1.

FIGS. 4A-4C are perspective views of a portion of the gas shutoff valveillustrating a principle of operation.

FIGS. 5A and 5B are a cutaway perspective views of two embodiments ofthe gas shutoff valve illustrating flow of gas through the valve when inthe open configuration.

FIGS. 6A-6D are side and top views of a portion of the gas shutoff valveillustrating positions of the valve ball in the open and closedconfiguration.

FIGS. 7A-7D are top and side views, respectively, of a portion of thegas shutoff valve illustrating an embodiment actuation mechanism.

FIGS. 8A and 8B are top and side views, respectively, of a portion ofthe gas shutoff valve illustrating another embodiment actuationmechanism.

FIGS. 9A and 9B are top and side views, respectively, of a portion ofthe gas shutoff valve illustrating another embodiment actuationmechanism.

FIG. 10 is a circuit block diagram and illustration of a controlprocessor and wireless transceiver circuit according to an embodiment.

FIG. 11 is a circuit block diagram of circuit elements may be used in anembodiment for controlling a motor actuator.

FIG. 12 is a top view of an embodiment antenna for use with the wirelesstransceiver.

FIG. 13 is a perspective diagram illustrating a valve position sensorcoupled to the valve body and to the control processor.

FIG. 14 is a communication network diagram illustrating communicationsamong a number of gas shutoff valves within a wireless ad hoccommunication network.

FIGS. 15 and 16 are process flow diagrams of a method that may beimplemented within the control processor for controlling variousoperations of the gas shutoff valve according to an embodiment.

FIG. 17 is a process flow diagram of an alternative method that may beused within the control processor for controlling operations of the gasshutoff valve according to another embodiment.

DETAILED DESCRIPTION

The various embodiments will be described in detail with reference tothe accompanying drawings. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.The drawings and references made to particular examples andimplementations are for illustrative purposes, and are not intended tolimit the scope of the invention or the claims.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any implementation described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other implementations.

While the various embodiments have particular utility as a shut offvalve for use in natural gas lines, such as on gas supply lines toresidences, the valve embodiments and the control mechanisms are notlimited to such applications. The embodiments may also be used toprovide a reliable, low cost and wirelessly-controlled shutoff valveuseful in any application in which such characteristics are beneficial.Other example applications include industrial gas supply lines, gaspipelines and distribution centers, gasoline and fuel oil supply lines,water lines, hydraulic lines, vacuum lines, and drain and vent lines.Also, while the descriptions of the various embodiments refer to naturalgas, the embodiments are not limited to a particular type of gas or gassupply line, and may be implemented on supply lines carrying propane,butane, methane, hydrogen, or any other combustible gas. Thus,references to “gas” and “natural gas” herein are merely for brevity andshould not be construed as requiring or being limited to a particulartype of fluid, unless specifically recited in the claims.

The various embodiments provide a low-cost safety valve for a gas linesand similar low pressure supply lines that can be remotely activated viaa wireless network that is self forming and adaptive to providereliability, flexibility and installation independent characteristics. Asimple but highly effective closure valve provides low leakage sealingusing a mechanism that is compatible with low energy actuators to enablelong life battery-operated control circuits. The valve can be configuredto be tamper proof and failsafe without significant changes to the valvedesign. A miniaturized controller and wireless network electronicsmodule provides the control mechanism for actuating the valve, as wellas reporting data regarding the valve status to external networks via anad hoc wireless network. A variety of simple magnetic valve operatingmechanisms can be implemented with the miniaturized electronic controlcircuits and the valve body. Such control actuation mechanisms enableself resetting or manual resetting valves. These unique features of thegas line shut off valve can provide important safety benefits at anaffordable price. Further, the remote actuating and sensing capabilitiesenabled by the electronics can save utilities substantial costs overmanually actuated safety and shutoff valves.

Wireless actuation of a gas shutoff valve offers important safetybenefits to the public as well, as to fire and rescue personnel. In theevent of a building fire or gas leak, emergency personnel can remotelyengage the shutoff valves from a safe distance. Such shutoff commandsmay be executed from a remote control center, as well as from wirelessactuators that may be installed in public safety vehicles. This remoteand local control capability is enabled by the ad hoc wireless networkthat is supported by the wireless communication and control electronics.Since the wireless transceivers used to communicate with ad hoc wirelessnetworks are highly affordable, all fire rescue and police vehiclescould be affordably equipped with such actuators. This would enablepublic safety personnel to promptly shut all gas lines in a buildingwithout having to wait for a gas utility worker to arrive on scene.Actuated valves can be easily reset after an emergency, but the tamperresistant design of the valve precludes unauthorized opening of thevalve, rendering the valves usable by utilities for controlling accessto the gas supply.

Since the wireless control circuitry is programmable, additional safetyfeatures and monitoring sensors can be added to the valve design atrelatively low cost. For example, temperature sensors, battery levelsensor circuits, valve position sensors and tamper detection sensors canbe added to the design, with information from these sensors relayed viathe ad hoc wireless network to utility servers. Additionally, the valveelectronics can be coupled to gas meters to provide a wireless gas meterdata delivery network. This would enable remote gas meter readingwithout the need for replacing current gas meters or installing adedicated communication network.

By using magnetic forces to maintain the valve ball in the openposition, the various embodiments provide a mechanism that enables thevalve chamber to be completely sealed to preclude gas leaks. To actuatethe valve (i.e., close the valve), the magnetic force holding the valveball into the open position is reduced or removed, thereby enabling thevalve ball to roll into the closed position under the influence ofgravity. The magnetic force of an exterior magnet may be removed by anumber of mechanisms. In addition to enabling the valve chamber to besealed, the use of magnetic forces to actuate the valve (or hold itopen) obviates any need for electrical wires and connections from thevalve chamber, which has safety advantages when implemented on supplylines carrying flammable or explosive fluids (i.e., gasses or liquids).

In a first example embodiment illustrated in FIGS. 7A-7D, an exteriormagnet is positioned on an actuator gear which when rolled to the closedposition moves the magnet away from the valve ball. This removes themagnetic force securing the ball in the open position, allowing it toroll to the closed configuration.

In a second example embodiment illustrated in FIGS. 8A and 8B, anexterior magnet positioned on the housing of the valve body is separatedfrom the valve body case by a thin electromagnet (i.e., a coil of wire,such as a pancake coil). To close the valve in this embodiment, thecontrol processor applies current to the electromagnet in a polaritythat generates a magnetic field opposite that of the exterior magnet.This applied magnetic field reduces the amount of magnetic force thatpasses through the valve body to engage the valve ball. When themagnetic force is reduced, the valve ball rolls into the closed positionas illustrated in FIG. 8B.

In a third example embodiment illustrated in FIGS. 9A and 9B, theexterior magnet is coupled to a solenoid type mechanism. To close thevalve in this embodiment, the control processor applies a current to thesolenoid which causes the exterior magnet to be withdrawn a shortdistance from the valve body. This additional separation between theexterior magnet and the valve ball reduces the amount of magnetic forceholding the ball in place, thereby allowing it to roll into the closedposition. Other mechanisms may be used for positioning an exteriormagnet or magnetic field so as to hold the valve ball in the openconfiguration and reducing the magnetic force applied to the valve ballto enable the valve to be closed.

The processor in the valve system can be reprogrammed and updated viathe ad hoc wireless communication network established by the processorwith nearby like-equipped gas valves. In this manner, improvements andupdates to the valve operating software can be deployed to all valves ina utility system without the need to individually service each valve.Further, authentication codes may be used to enable the valve controlelectronics to confirm that a valve shut command has been issued by anauthorized computer or authority. Such authentication codes may beupdated via the ad hoc wireless communication link. Periodic revisionsto the command authentication codes may be transmitted in order toensure that the valves do not become vulnerable to unauthorizedactuation, such as by hackers.

In a further advantage provided by the various embodiments, the valveball is held in place by a magnetic force which may be overcome bysevere shaking or shock to the valve body. Thus, the embodiments providea mechanism for automatically shutting gas lines in the event of asevere earthquake.

In an embodiment, the valve control electronics may include atemperature sensor, such as a thermistor, coupled to the controlprocessor. The control processor may be configured throughprocessor-executable software to monitor the temperature sensor andcompare sensed temperatures to a maximum permissible value. In the eventthat the sensed temperature exceeds the maximum permissible temperature,the processor may automatically shut the valve by removing the magneticforce applied to the valve ball. In this matter, the valve can beconfigured to automatically shutoff the gas supply when temperatures inthe vicinity of the valve indicate that the fire is present. Thiscapability can reduce the chance for explosion in event of a buildingfire.

Other types of sensors may also be implemented with the variousembodiments to provide further safety features. For example, a carbonmonoxide sensor may be coupled to the control electronics, which may beconfigured with software to shut the valve in the event that measuredcarbon monoxide levels exceed a safe level. In this manner, the gassupply to a malfunctioning furnace, dryer, water heater, oven or othergas appliance may be shut off to minimize the chance of injury or deathfrom carbon monoxide poisoning. An audible alarm may also be included aspart of the valve assembly, and sounded by a signal from the controlprocessor if a dangerous condition is sensed. As another example,natural gas sensors may be coupled to the valve electronics which may beconfigured with software to actuate the valve (i.e. close the valve) inthe event that the sensor indicates the presence of natural gas in theexterior atmosphere at levels exceeding a safe level. In this manner,the valve body valve assembly can automatically actuate to reduce thepotential for explosion in the event of a gas leak somewhere within thebuilding. Other safety implementations may be implemented by leveragingthe programmable processor coupled to the valve actuation mechanism.

In addition to closing the valve in response to a sensed safetycondition, such as any of tampering, high temperature, high carbonmonoxide levels, or high gas levels, the control processor may also beconfigured to send an alarm message via the ad hoc wirelesscommunication network to a server or control center. In this manner, thegas valve can alert authorities to the sensed condition, which may allowan appropriate response (e.g., fire, paramedic or gas company personnel)to be dispatched to the location in a timely manner without actions bythe occupants (who may incapacitated, asleep, etc.). Thus, the variousembodiments may be integrated with a region's public safety services atno additional cost to consumers, the utility or the community.

FIG. 1 shows a top view of an embodiment wireless gas shutoff valve 1.The wireless gas shutoff valve 1 includes a valve assembly 2 and anelectronics module 3. A threaded opening 4 may be provided in a topsurface of the gas valve configured to be threaded onto a standard gassupply pipe. In the embodiment illustrated in FIG. 1, the electronicsmodule 3 includes an antenna assembly 5 that the electronics circuitryuses to establish wireless communication links with other similarlyequipped gas valves, as well as with gateway and remote operator modulesas described below with reference to FIG. 14.

FIG. 2 shows an exploded view of a wireless gas shutoff valveillustrating components of an example embodiment. A key element of thevarious embodiments is the wireless communication and controlelectronics 10 which enable programmable control of the valve and datacommunications via self established (i.e., “ad hoc”) wirelesscommunication networks. The wireless communication and controlelectronics 10 includes a control processor coupled to a wirelesstransceiver as described more fully below with reference to FIG. 10. Thewireless communication and control electronics 10 is included within theelectronics package 3 that is attached to the valve assembly 2 andenclosed by a cover 12.

The other key element of the various embodiments is the valve assembly 2that is attached to the electronics package 3. The valve assembly 2includes a valve ball 30 that moves freely within a valve interior 32formed within a valve body 18. The valve interior 32 includes a valveseat 78 (see, e.g., in FIG. 4A) configured to form a seal with the valveball 30 when the valve is in the shutoff configuration. Detailsregarding the valve seat are described below with reference to FIGS.4A-4C. The valve interior 32 may be sealed on one side of the valve body18, while the opposite side is sealed by a closure plate 20. The closureplate 20 may include a cutout portion 34 that cooperates with surfaceswithin the valve body 18 to form a ramp on which the valve ball 30 isinduced to roll towards the valve seat 78 as described below withreference to FIGS. 4A-4C.

The valve interior 32 may be sealed on a top surface with a valveclosure head 14. A ceiling O-ring 16 may be position to form a gas tightseal between the valve body 18 and the valve closure head 14.

As mentioned above, in the various embodiments the valve ball 30 is heldin an open position by magnetic forces applied by a magnet 36 that isexterior to the valve body 18. Thus, the valve interior 32 can becompletely sealed, with no valve actuation mechanisms penetrating thevalve body (other than magnetic fields). The valve ball 30 is made froma ferromagnetic alloy, such as steel, nickel, an iron-nickel alloy, etc.In some embodiments, the ferromagnetic ball may be covered by aprotective layer (not shown), such as plated metal, cladding or plastic(e.g., Teflon®) to protect the valve ball or enhance its operationalreliability. In the embodiment illustrated in FIG. 2, this exteriormagnet 36 may be moved with respect to the valve ball 30 by means of anactuator gear 38 that pivots about an axel 40 coupled to the valve body18. In this embodiment, the exterior magnet 36 fits within an opening 37in the actuator gear 38, as described more fully below with reference toFIGS. 7A-7D. The actuator gear 36 may be rotated by a drive gear 42 thatis coupled by an axel 44 to a drive motor 46. The drive motor 46 iselectrically coupled to the wireless communication and controlelectronics 10, as described in more detail below with reference toFIGS. 10 and 11.

In order to provide protection from tampering, the embodimentillustrated in FIG. 2 includes features that prevent unauthorizeddisassembly. In the illustrated embodiment, the valve body 18 is coupledbetween the closure plate 20 and a gear support plate 22, with theassembly held in place by fastening means or fasteners (e.g., bolts,rivets, etc.) passing through fastener holes 50. Any of a variety ofconventional threaded fasteners may be used for coupling the closureplate 20, gear support plate 22 and valve body 18 together. To preventunauthorized access to the threaded fasteners, the closure plate 20 maybe covered by an inner cover plate 24 which connects to the closureplate 20 by means of a sliding attachment, such as a trapezoidal slidingdovetail connection as illustrated. Similarly, the gear support plate 22may be covered by an outer cover plate 26 which likewise connects to thegear support plate 22 by a sliding dovetail connection or similarfastener-less attachment means. The use of a sliding attachmentmechanism for connecting the cover plate 24, 26 to the closure plate 20and gear support plate 22 enables the assembly to be locked together bymeans of a locking bolt that passes through locking bolt through holes52 to prevent sideways movement of the cover plates 24, 26. Such alocking bolt 54 and lock 56 is shown in FIG. 3.

FIG. 3 shows a perspective view of an embodiment which shows theelectronics package 3 with the cover 12 removed to reveal the wirelesscommunication and control electronics 10 and a battery 62 that powersthe electronics and the actuator motor 46. In addition to housing thewireless communication and control electronics 10 and the battery 62,the electronics package 3 may include an interior volume 60 that mayhold additional sensors as well as connectors for connecting to otherdevices, such as a gas meter (not shown). Also, the assembly includes anantenna 100 coupled to the transceiver 104 (see FIG. 10), that isdesigned to transmit and receive radio frequency signals. The antenna100, it may be position on the electronics package 3 (as shown in FIG.3) or on the valve assembly 2, such as on a top surface of the valveclosure head 14, so that such structures become an integral part of theantenna design and improve antenna gain and impedance matching.

As mentioned above, the embodiments may be made tamperproof by means ofa locking bolt 54 that passes through the valve body 18, cover plate 24and gear cover plate 22. A lock 56 may be provided in the locking bolt54 to permit the disassembly of the valve by one possessing acorresponding key.

FIGS. 4A-4C illustrate details of the valve body which enable closure ofthe valve by movement of the valve ball 30 due to gravity. Referring toFIG. 4 A, a bottom portion of the valve body 70 includes a cutoutportion 74 which forms a V-shaped structure 72 that leads to the valveseat 78. As shown in FIG. 4B, the valve ball 30 rests on the edges ofthe cutout portion 74 of the bottom portion of the valve body 70. Sincethe edges of the cutout portion 74 diverge in the V-shaped portion 72,the valve ball 30 will rotate under the influence of gravity towards thevalve seat 78. As a result, without any forces holding the valve ball 30in place at the narrow end of the V-shaped structure 72, the ball willroll down and drop onto the valve seat 78, thereby blocking the exitport 76, as shown in FIG. 4C.

FIG. 5A shows a cutaway view of a first embodiment of the valve bodywith a valve ball 30 in the open configuration to illustrate gas flowthrough the valve. As illustrated, fluid (e.g., natural gas or propane)flows through the threaded opening 4 at the top, such as from aconnected gas supply line, around the valve ball 30 within the valveinterior 32 and out the exit port 76, which may be threaded onto a gasline within the building in which the valve is installed. Provided thatthe valve ball 30 is in the open position, a large volume within thevalve interior 32 permits gas to flow through the valve with very littlepressure drop. However, when the valve ball 30 is in the closed positionand resting on the valve seat 78, flow through the valve is prevented.

FIG. 5B shows a cutaway view of a second embodiment of the valve bodywith a valve ball 30 in the open configuration to illustrate gas flowthrough the valve. In this embodiment the valve inlet port 4 ispositioned inline with the valve exit port 76 so that fluid flowsstraight through the valve which may reduce the pressure drop caused bythe valve. Such configurations may be useful in low-pressure fluidsupplies, such as natural gas lines.

FIGS. 6A-6D illustrate further details of the bottom portion of thevalve body 70 showing the valve ball 30 in the open configuration (FIGS.6A and 6B), and in the closed configuration (FIGS. 6C and 6D). As shownin these figures, the valve seat 78 may be formed as a conical surfaceangling upward from the exit port 76 to the rest of the cutout portion74. The angle and diameter of the conical valve seat 78 may be selectedto reliably form a gas tight seal with the valve ball 30 when it is inthe closed configuration as illustrated FIGS. 6C and 6D. Due to theV-shaped structure 72 and the lower portion of the valve seat 78, thevalve ball 30 will tend to remain seated on the valve seat until movedby an exterior magnetic force as described more fully below. Thus, oncethe valve ball 30 is released as part of a valve actuation, the valvewill remain in the closed configuration until an affirmative action istaken to reset the valve.

FIG. 6A also illustrates how the exit port 76 may include threads 80which may be configured to form a threaded coupling with a standard gasline. So configured, the valve assembly can be attached to the valveline of a building simply by rotating the valve assembly to thread theexit port onto the threads of the valve line.

The V-shaped structure 72 enables gravity to move the valve ball 30 tothe closed position with a wide tolerance on the angle of the valve wheninstalled. Even if the valve is installed at an angle with respect tovertical such that the V-shaped structure 72 rises in the direction ofthe valve seat 78, the V shape will ensure that the valve ball 30 rollstowards the valve seat. However, such a V-shaped structure is notessential to the invention, and other configurations may be used toachieve the same purpose. For example, the valve assembly may berequired to be installed in a level condition, in which case theV-shaped structure 72 may be replaced with a simple inclined plane.

As mentioned above, the various embodiments use magnetic forces to holdthe valve ball 30 in the open configuration, such as at the narrow endof the V-shaped structure 72. To conserve battery power, such forces maybe applied by an exterior permanent magnet 36, such as a rare earthmagnet. For example, such a magnet may be made from neodymium or aneodymium-iron-boron (NdFeB) alloy. The valve body 18 may be made from anon-ferrous alloy, such as brass, which permits the magnetic field topass from the exterior of the valve body 18 to the valve interior 32.When the exterior magnet 36 is positioned against the exterior surfaceof the valve body 18 at the narrow end of the V-shaped structure 72, themagnetic field reaching the valve ball 30 will be sufficient to hold itin position. To actuate (i.e., close) the valve, the exterior magnet 36only needs to be moved away from this position far enough to reduce themagnetic forces on the valve ball 30 to the point where gravity causesthe valve ball to roll to the closed configuration.

In an embodiment illustrated in FIGS. 7A-7D (which is also illustratedin FIG. 2), the exterior magnet 36 is coupled to an actuator gear 38which when rotated to the position illustrated in FIGS. 7A and 7B,positions the magnet adjacent to the location of the valve ball in theopen configuration. So positioned, when the valve ball 30 is moved tothe open configuration position, the magnetic fields from the externalmagnet 36 will hold it in place. To actuate (i.e., close) the valve, theactuator gear 38 is rotating so as to move the exterior magnet 36 awayfrom the valve ball 30. As illustrated in FIGS. 7C and 7D, this may beaccomplished by rotating the drive gear 42 to cause the exterior magnet36 to move up and away from the valve ball 30. Released from themagnetic fields of exterior magnet 36, the valve ball 30 then rolls downthe V-shaped structure 72 and engages the valve seat 78.

Another example embodiment that applies a controllable exterior magneticfield to the valve ball 30 is illustrated in FIGS. 8A and 8B. In thisembodiment, the exterior magnet 36 remains in the same position on anexterior wall 84 of the valve body 18. In order to reduce the magneticforces passing through the valve body wall 84, an electromagnet 80 ispositioned between the wall 84 and the permanent magnet 36. Theelectromagnet 80 is electrically connected by wires 82 to the wirelesscommunication and control electronics 10. In an example embodiment, theelectromagnetic 80 may be in the form of a planar or pancake coil ofwire. To actuate (i.e., close) the valve, an electric current is passedthrough the electromagnet 80 with a polarity that induces a magneticfield which is opposite to that of the electromagnet 36. As aconsequence of this reversed magnetic field, the net magnetic fieldpassing through the valve wall 84 to be the valve ball 30 will bereduced to the point where the valve ball rolls towards the closedposition under the force of gravity. This embodiment has the advantageof fewer moving parts. Since the electromagnet 80 only needs to beenergized for a few seconds in order to actuate the valve, and valveactuation is presumed to be a rare occurrence, this embodiment shouldnot result in a significant shortening of the battery life even thoughsignificant power may need to be applied to sufficiently disrupt themagnetic field of the external magnet 36.

A third example embodiment of a mechanism for controlling an externalmagnetic field is illustrated in FIGS. 9A and 9B. In this embodiment,the external magnet 36 is coupled to a solenoid 86, which includes aspring 88 that normally holds the external magnet 36 in close proximityto the valve wall 84 as illustrated in FIG. 9A. The solenoid 86 iselectrically coupled to the wireless communication and controlelectronics 10. To actuate (i.e., close) the valve, an electric currentis applied to the solenoid 86, which causes it to retract the externalmagnet 36, thereby moving it away from the valve wall 84 as illustratedin FIG. 9B. This increased distance between the external magnet 36 andthe valve ball 30 reduces the magnetic forces on the ball so that thevalve ball 30 rolls down the V-shaped structure 72 and into the valveseat 78.

The embodiments illustrated in FIGS. 7A through 9B are intended asexamples of mechanisms that can be used to control an external magneticfield in order to cause actuation of the valve. Other mechanisms mayalso be used to achieve the same purpose. Also, some of the elements ofthe embodiments illustrated in FIGS. 7A through 9B may be combined orused with other features to accomplish the same purpose. For example,instead of connecting the external magnet 36 directly to a solenoid 86,a solenoid may be configured to move one end of a lever which causes amagnet on the other end of the lever to move much larger distance. Asanother example, a solenoid may be used to move the external magnetlaterally or vertically, similar to how the magnet is moved by theactuation gear 38 illustrated in FIGS. 7A-7D.

Once the valve is in the closed configuration with the valve ball 30resting on the valve seat 78, the valve will remain in the closedconfiguration until an external magnetic force is applied to lift thevalve ball 30 back to the open configuration. In an embodiment, thisvalve reset operation may be accomplished by an individual applying astrong magnet to the outside of the valve assembly 2 and moving themagnet so as to lift the valve ball 30 back to the open position. Thismay be accomplished by a person placing a strong external magnet againstthe valve assembly just above the outlet of the valve and then movingthe magnet along the side of the valve until it is under the supplyinlet. Since the valve ball 30 will not remain in the open configurationunless the actuation gear 38 has been rotated so that the externalmagnet 36 is adjacent to the open location (e.g., shown in FIG. 7B),this valve reset operation cannot be performed without authorization(i.e., transmission of a valve open command). However, it is a simpleenough procedure that a homeowner could perform the valve reset once autility has transmitted a valve open command. For embodiments such asillustrated in FIG. 8A-9B, unauthorized resetting may be detected by thevalve control processor sensing that the valve ball 30 is in the openconfiguration when a status bit in memory indicates that the valveshould be closed. As described below with reference to FIG. 17, theprocessor may detect such an unauthorized open situation and re-performthe valve closure actuation.

In another embodiment, which may be implemented as a variation of theembodiment described above with reference to FIGS. 7A-7D, the valveactuation gear 38 and external magnet 36 may be configured so thatmovement of the gear can cause the external magnet 36 to follow a pathalong the side of the valve body 18 that will lift the valve ball 30back to the open configuration. For example, the actuation gear 38 maybe positioned so that rotation of the gear causes the external magnet 36to rotate below the valve body 18 to cause the valve ball 30 to rollinto the shut configuration, while additional rotation causes theexternal magnet 36 to rotate past the valve seat 78, thereby lifting thevalve ball back onto the V-shaped structure 72 and back up to the openconfiguration. Thus in this embodiment, the valve shut actuation mayinvolve rotating the actuation gear 38 through 90° (or so), while thevalve open actuation involves rotating the actuation gear 38 in the samedirection through 270° (or so).

An example embodiment of the wireless communication and controlelectronics 10 is illustrated in FIG. 10. In general, such electronicswill include a processor or microcontroller 102 coupled to a wirelesscommunication radio transceiver 104 which is coupled to an antenna 100.In an embodiment, the radio transceiver 104 is configured to send andreceive RF signals according to the IEEE 802.15.4 standard. Theprocessor 102 and radio transceiver 104 together may be configured toautonomously establish ad hoc wireless networks with other similardevices, such as are enabled by the ZigBee or 6LoWPAN communicationprotocols. In some embodiments, the processor 102 may include analog anddigital input/output (I/O) circuits. The processor 102 may be coupled tothe memory 106, such as flash memory, for storing programs and data,including sensor data. The processor 102 may also be coupled to readonly memory 108 for storing a serial identifier that the processor 102can communicate other devices in order to identify itself. The processormay also be coupled to standard connections, such as a USB connector112, 6 pin connectors 116, and 10 pin connectors 118 to enableconnecting with other components within the valve assembly, as well asreceiving programming and configuration data during assembly and test.The wireless communication and control electronics 10 will also includeconnections to battery power, as shown on FIG. 11, and other controlcircuitry. In an embodiment, the processor 102 may be coupled to anactuator control circuit 114 which includes components necessary toreceive control signals from the processor 102 and transform them intosignals or currents sufficient to achieve actuation of the valveactuator mechanism, such as a drive motor 46, electromagnet 80, orsolenoid 86.

As illustrated in FIG. 10, modern electronics enables the components ofthe wireless communication and control electronics 10 to be assembled ina small circuit board or chipset configuration. Further, the variouscomponents may be integrated into one or a few application specificintegrated circuit (ASIC) to further reduce the size and cost of theelectronic components.

The radio transceiver 104 may be configured to communicate using any ofa variety of known communication technologies and protocols, including,for example, WiFi, BlueTooth®™ (which communicates using the 2.4 GHzfrequency band), UWB (Ultra Wideband), IEEE 802.15.4, and ZigBeewireless communication protocols and standards. In a preferredembodiment, the transceiver 106 complies with the IEEE 802.15.4communication protocol or the ZigBee specification, which are knownprotocols for automatically establishing ad hoc wireless communicationnetworks. The IEEE 802.15.4 communication standard and the ZigBeespecification are hereby incorporated by reference.

The control processor 102 may be any programmable microprocessor,microcomputer or microcontroller that can be configured by softwareinstructions to perform a variety of functions, including the functionsof the various embodiments described herein. In a preferred embodiment,the control processor is of a type known as a “mote” which is aminiaturized microcontroller that is optimized for use with devicescomplying with the ZigBee specification. For example, in an embodiment,the control processor may include a “Single-Chip 2.4 GHz IEEE 802.15.4Compliant and ZigBee™ Ready RF Transceiver” (part number CC2420), and a“16-Bit Ultra-Low-Power MCU, 8 KB Flash, 2 KB RAM, CC1101 Radio,AES-128, 12 Bit ADC, USCI” (part number CC430), both manufactured byTexas Instruments, Inc.

Since the wireless communication and control electronics 10 based upon aprogrammable control processor 102, the functionalities of theelectronics can be defined by the processor-executable instructions usedto program the processor. An example of operations that may beprogrammed into the processor 102 are described below with reference toFIGS. 15-17.

In the various embodiments, wireless communication and controlelectronics 10 may be designed using power efficient components tominimize the power drain on a battery or other power source. Further,the control processor 102 may be configured with software to minimizepower drain by minimizing the time that the electronics are energized.For example, the processor may be configured to place itself and othercomponents in a low power “sleep mode” a majority of the time. Theprocessor may wake up and energize the wireless transceiver 104periodically and for a brief interval to check whether there are anywireless communications that need to be received and processed. Further,the processor may be configured to wake up and monitor RF signals on aknown schedule synchronized among all similarly equipped valves tofacilitate establishing ad hoc wireless communication networks forperiodically relaying sensor and the status data to a central monitoringfacility. In such embodiments, the drain on the battery 62 may bereduced to the point where the valve can operate for several yearswithout requiring servicing. Methods for reducing power demand ofwireless electronics are well known in the wireless communications arts,including other wireless devices designed according to the ZigBeespecification.

The wireless communication and control electronics 10 may include anactuator control circuit to enable the low power control processor 102to activate the valve actuator mechanism, which may require higher powerthat supplied to the processor. FIG. 11 illustrates an example of suchan actuator control circuit according to an embodiment. In this examplecircuit, the control processor 102 is coupled via a connector 118 to agate logic circuit U1 provide fail-safe operation. Actuation controlsignals from the control processor 118 provided to the gate logiccircuit U1 causes corresponding signals to be sent to switchingtransistors Q1, Q2, Q3 and Q4, which when energized couple the actuatormechanism, such as motor J2, to the battery 62. In the illustratedexample circuit, the switching transistors are connected to the gatelogic circuit U1 so that the polarity of voltage applied to the motor J2can be controlled, so as to be able to drive the motor in two differentdirections. When no pulse is applied to the switching transistors Q1,Q2, Q3 and Q4, the motor J2 remains coupled to ground. Resistor elementsR1 through R9 are included in the circuit to balance voltages andminimize bypass currents.

FIG. 11 also illustrates an example circuit for coupling the controlprocessor 102 to a sensor, such as a Hall Effect sensor J3. The circuitenables the control processor 102 sense when the valve ball 30 is in theopen or closed configuration by sensing its magnetic field via the HallEffect sensor J3 which may be placed in an appropriate location on thevalve assembly 2, as shown in FIG. 13. Other types of sensors, such astemperature sensors may be electrically coupled to the control processor102 using similar circuits as are well known in the art.

It will be appreciated by one of skill in the electrical arts that thecircuit design illustrated in FIG. 11 is but one example of a controlinterface circuit that may be utilized in the various embodiments. Othercontrol circuits may be used, particularly to meet the requirements ofdifferent types of actuation mechanisms (e.g., electromagnet 80,solenoid 86) which may require different levels of current and voltageas well as different control signals.

In order to improve antenna gain, the various embodiments may positionthe antenna 100 on the valve assembly 2 or electronics package 3 so thatthe metal structures of the modules become an antenna ground plane orother integral part of the antenna. This is illustrated in FIG. 12. Thisconfiguration optimizes the antenna for maximum gain and powerefficiency. Another embodiment may incorporate an antenna design that iselliptically polarized to improve response to multipath signals andimprove sensitivity. Further embodiments may implement diversitytechniques within the antenna structure to decrease effects of multipathfading and improve wireless link quality.

As mentioned above, a variety of sensors may be coupled to the wirelesscommunication and control electronics 10 for gather informationregarding the valve condition (e.g., open vs. closed), externalconditions (e.g., temperature, gas concentrations, etc.), and tampering.A wide variety of sensors may be used for this purpose. For example,FIG. 13 illustrates a Hall Effect sensor 120 coupled to the valveassembly 2 at a position that enables it to detect the position of thevalve ball 30 by sensing the local magnetic field. For example, sincethe valve ball 30 is held in the open position by an external magneticfield, the magnetic field in the vicinity of the Hall Effect sensor 120will be stronger when the valve ball 30 is in the open position.Comparing the signal from the Hall Effect sensor 120 against a thresholdvalue stored in memory enables the control processor 102 to determinewhen the valve ball 30 is an open configuration.

Including a radio transceiver 104 configured to establish ad hocwireless communication networks, such as the IEEE 802.15.4 standard,enables the various embodiments to reliably communicate data and receiveactuation command signals without requiring the establishment of fixedcommunication networks. Thus, as embodiment valves are installed instructures, they will automatically detect other similarly configuredvalves within the vicinity and establish ad hoc networks autonomously.As new valves are installed within the same building or adjacentbuildings, the ad hoc communication network will add such communicationnodes to the wireless network. If any valve is removed (such as throughtampering or loss of battery power) the ad hoc communication networkwill reconfigure, passing messages via the remaining active nodes.Further, ad hoc communication networks will autonomously configurethemselves to reach out to a gateway node which may then connect towide-area networks, such as telephone lines or the Internet. In thismanner, valves within an ad hoc communication network can transmit datamessages to a central server or facility, with the messages passingthrough the various nodes of the ad hoc network until they are receivedby a gateway node which then relays the messages via conventionalnetwork or Internet protocols. The methods and technologies forestablishing such wireless ad hoc communication networks are well knownin the arts and routinely used by devices designed according to the IEEE802.15.4 and ZigBee standards.

In addition to providing robust and reconfigurable wireless networks,the radio transceiver 104 configured to establish ad hoc wirelesscommunication networks of the various embodiments also enables groups ofvalves (e.g., the valves within a single building) to collaboratively orin aggregation by exchanging information and applying decisionalgorithms based upon aggregate sensor data and states. By sharingsensor data among a network aggregation of wireless shutoff valves, theaggregate may be able to detect, recognize and/or act upon sensorconditions building-wide hazards that fall below the decision thresholdin any one valve. For example, if the electronics of several valvesmeasure elevated levels of carbon monoxide or explosive gas, theaggregate may be recognize a fault condition and initiate an automaticactuation even when the concentration near any one valve is within safelimits. As another example, a network aggregation of valves mayrecognize a hazardous condition warranting automatic valve actuationbased upon low gas pressure readings. As a further example, elevatedtemperature readings reported by a number of valves, perhaps incombination with a report of automatic actuation of one valve inresponse to a local elevated temperature may be processed by the networkaggregate to recognize a building fire and initiate an automaticactuation of all valves in the building. Such aggregate cooperation anddecision making may be implemented in the various embodiments throughappropriate software programming of the valve control processors.

Another advantage provided by the radio transceiver 104 of the variousembodiments is the ability of the wireless shutoff valves toautonomously establish ad hoc point-to-point wireless communicationlinks with a suitably configured (e.g., with proper authentication codesor IDs) communication node, such as may be installed in a utility orpublic safety vehicle or carried by a utility worker. Suchpoint-to-point wireless communication links may be establishedautomatically as a communication node come within communication range ofa wireless shutoff valve, such as when a suitably equipped vehicledrives by a building in which the valve is located. This enablescommunications to be established on a “drive by” basis, which may beuseful in the event of a network issue (failure, disruption, etc.),failure of a neighborhood gateway node, and in installations too farremoved from other valves or gateway nodes to establish a communicationnetwork link back to a home server, such as in rural neighborhoods wherehomes are located far apart. For example, in the event of a naturaldisaster, such as an earthquake or hurricane that knocks out normalcommunication networks (e.g., telephone and Internet) and/or power, thiscapability would enable utility or public safety officials to determinethe valve configuration (i.e., open or closed), as well as gather othersensor data, from all valves within a neighborhood merely by driving asuitably equipped vehicle past the buildings.

In a further application of these capabilities, the control processor102 may be configured with processor-executable instructions to store inmemory 106 sensor data (e.g., valve position, temperature, pressure,external conditions) and/or data received from an external meter (e.g.,a nearby gas or water meter) until such data is successfullycommunicated by an ad hoc wireless network. As described below withreference to FIG. 15, the control processor 102 may receive data from avariety of sensors and store the data in memory 106 and then transmitthe data periodically or in response to a query. By storing sensor datauntil transmitted, the various embodiments enable wireless shutoffvalves to retain weeks or months worth of data that can then bedownloaded simply by moving a suitable communication node (e.g., withina utility vehicle) within communication range of the valve. Using alarge enough memory 106, substantial sensor data, such as six monthsworth of data may be stored within the valve electronics. In thismanner, utility and public safety personnel can obtain the stored data(e.g., the past six-months worth of sensor data) from valves located ina neighborhood simply by driving through in a suitably equipped vehicle.This capability may be also be useful in the event of communicationsystem disruptions, be they natural (e.g., earthquake, hurricane, etc.)or man-made (e.g., power cut off, disconnected networks or jamming),since the valve electronics are battery powered and will retain sensordata in memory until downloaded, such via a point-to-point network linkestablished during a “drive by.”

This communication network is illustrated in FIG. 14 which shows aplurality of embodiment valves 1 a through 1 d position within variousstructures 130 a-130 d. Each valve 1 a-1 d establishes a wirelesscommunication link 132 with each other valve within range of thewireless link. For example, valve 1 b establishes a wirelesscommunication link 132 with nearby valves 1 a and 1 c. Similarly, valve1 c establishes a wireless communication link 132 with nearby valves 1 band 1 d, and valve 1 d establishes a wireless communication link 132with nearby valves 1 c and a gateway node 134 positioned on a nearbyutility pole. In the illustrated example, the gateway node 134 iscoupled via a hard wire network 136 to a central server 138, but mayalso or alternatively be coupled to the Internet 140. As a result ofestablishing such a wireless ad hoc communication network, valve 1 a cansend a message to the central server 138 by relaying the message throughthe other members of the ad hoc wireless network, namely the valves 1 b,1 c and 1 d to reach the gateway node 134. Similarly, the central server138 can send command messages to valve 1 a via the other valves 1 b, 1 cand 1 d in the ad hoc wireless network.

An additional benefit of using wireless ad hoc networks is that othersuitably equipped communication nodes can connect to the communicationnetwork in order to receive data signals and transmit actuationcommands. For example, FIG. 14 illustrates a utility truck 146 equippedwith the suitable wireless ad hoc communication transceiver 144. Whenthe utility truck 146 drives within the communication range of any valve(e.g., valves 1 a, 1 b), the truck's transceiver 144 and the nearbyvalves 1 a, 1 b establish wireless communication links 132 whicheffectively adds the truck transceiver 144 to the ad hoc communicationnetwork. So connected, the utility truck 146 can now receive data fromeach of the valves 1 a-1 d communicating via the ad hoc communicationnetwork. Also, the utility truck 146 can issue actuation commands to anyvalves 1 a-1 d communicating via the ad hoc communication network. Thus,the utility truck 146 can issue commands to shut any one of the valves 1a-1 d in the network, without the need to have the commands sent fromthe central server 138. Thus, by equipping all vehicles used by publicsafety (e.g., police, fire, rescue, etc.) with an appropriate configuredcommunication transceiver 144, any authorized public safety official canshut valves within structures in the event of an emergency withouthaving to physically enter the structures. Also, no special valveactuation tools are required, and the cost of the communicationtransceiver 144 (or configuring existing radios to access the wirelessad hoc networks) may be very affordable.

An additional benefit of the various embodiments is the data relayed tothe central server 138 from the various valves 1 a-1 d may be stored ina database, such as an SQL database which may be coupled to a Web serverhosted within the central server 138, so that information can be madeavailable via computers 142 coupled to the Internet 140. In this manner,public safety personnel, such as police and fire dispatchers, as well asutility personnel can monitor the condition of gas valves throughout thecommunity from their desktop, laptop or dashboard computers. Individualswith appropriate passwords and credentials may also be permitted toissue valve closure actuation commands via the central server 138 bysending commands to the server via the Internet 140, such as from apersonal computer 142 or smart phone 144 (e.g., via an app on aniPhone®) with Internet access. The central server 138 may receive andauthenticate such shut commands, and then send an appropriate valve shutcommand to the indicated valve 1 a-1 d via the wireless ad hoccommunication network.

In order to provide security and avoid inadvertent or unauthorizedclosure of valves, each valve may be configured with a uniqueidentifier, such as may be stored in a serial ID 108, and that thewireless communication and control electronics 10 can be used toidentify itself to nodes within the wireless ad hoc communicationnetwork, as well as to recognize messages addressed to the valve.Additionally, wireless communication and control electronics 10 maystore authentication codes and/or associated cryptographic algorithmswhich may be used by the control processor 102 to authenticate incomingcommand messages.

In a further embodiment, the location (e.g., address, room and floor) ofeach installed the valve 1 a-1 d may be recorded in a database, such asmay be maintained on the central server 138. This capability wouldenable alarm messages communicating notable conditions, such as fire,tampering, valve actuation, etc., to be correlated to the preciselocation of the valve to enable prompt dispatch of fire, safety orutility personnel if appropriate.

In a further embodiment, wireless communication and control electronics10 may be configured to estimate their own location relative to thelocation of nearby valves by using signal strength as a rough measure ofseparation distance and triangulation techniques. If some communicationnodes, such as gateway nodes, are in a known reference position (e.g.,on a telephone pole), valves can determine and report their estimatedpositions with respect to such reference locations. This ability tocalculate their location from known reference points may enable valveelectronics to generate or confirm valve location data without relyingon installation data that may be incorrect or unavailable.

In a further embodiment, this relative location estimating capabilitiesmay be used to provide public safety personnel with the approximatelocation of valves with respect to a vehicle equipped with acommunication node 144 without accessing the central server 138. Bytransmitting a request for relative position reports, an appropriatelyconfigured transceiver 144 in a public safety vehicle can receive arelative location (e.g., bearing and distance) of a valve that isreporting an error condition (e.g., fire, elevated CO, etc.). Thiscapability may be enhanced by positioning three communication referencenodes at various known locations along a city block to provide referencelocations that can enable more accurate location of each reporting valvewithin three dimensions. Such self generated location reportingcapabilities may aid fire and safety personnel to locate valves ornearby structures in the presence of smoke or sever structural damage(such as caused by earthquake, floods, or sever weather).

In a further embodiment, a home or building security system may beconfigured with a communication node that can send commands to anembodiment gas shutoff valve, with the security system configured tosend a gas line shut off command via the wireless ad hoc communicationnetwork in the event of certain types of alarms, such as fire, highcarbon monoxide levels, high gas levels, break in, etc.

Since the valve wireless communication and control electronics 10 areprogrammable, the functions of the various embodiments may beimplemented by programming the control processor 102 with suitableprocessor-executable instructions. An example embodiment method 150 thatmay be implemented within the valve wireless communication and controlelectronics 10 is illustrated in FIGS. 15 and 16.

Referring to FIG. 15, the control processor 152 may be programmed towake up from a power conserving sleep state in step 152. As mentionedabove, control processor 102 may be configured to minimize the amount oftime it is in a high power state. A low power timer circuit may be usedto determine when the control processor 102 should wake up. For example,a timer or the control processor 102 may be configured to wake up everyfew seconds to detect whether there are any communications via an ad hocwireless network that need to be received. Also, a variety of interruptsand state sensing circuits may be used to signal when the controlprocessor 102 should wake up, such as to respond to a sensed condition.In order to conserve power, the control processor 102 may be configuredto quickly determine whether further actions are required, and if not,promptly return to a low power state. For example, in method 150, theprocessor may check a timer to determine whether it is time to gatherand transmit sensor data in determination step 154. If the processordetermines that it is time to transmit sensor data (i.e., determinationstep 154=“Yes”), the processor may receive sensor inputs or send signalsto sensors in order to query various connected sensors, and store anyreceived sensor data in step 156. Examples of sensors that may bequeried include temperature sensors (e.g., thermisters), pressuresensors, gas concentration sensors (e.g., CO and/or natural gasconcentration), battery level measuring circuits, gas meter indicators,etc. The processor may then format the received data for transmission insuitably addressed message packets in step 158.

With data ready for transmission or if the processor determines that itis not time to transmit sensor data (i.e., determination step 154=“No”),the processor may energize the radio transceiver 104 and monitor forwireless network signals in step 160. This step may involve merelymonitoring radio frequency signals or logging into an establishedwireless ad hoc communication network. In determination step 162, theprocessor may determine whether a signal has been received via the radiotransceiver. If the processor determines that no signal has beenreceived (i.e., determination step 162=“No”), the processor maydetermine whether there is data to send in determination step 164. Ifthere is no data to send (i.e., determination step 164=“No”), theprocessor may promptly returned to the sleep state in step 170.

If there is no established ad hoc communication network and theprocessor has data to transmit (i.e., determination step 164=“Yes”), theprocessor may transmit the handshaking signals necessary to establish anad hoc wireless communication network with nearby devices in step 166.Once a wireless ad hoc communication network is established, theprocessor may transmit the data packets via the network in step 168.Once all data packets have been transmitted, the processor may return tosleep state in step 170.

If upon monitoring for wireless network signals in step 160 theprocessor receives a signal (i.e., determination step 162=“Yes”), theprocessor may determine how to respond to that signal by evaluatingwhether the received message is intended for the processor or foranother addressee in determination step 172. If the received message isa message packets addressed to another node (e.g., the central server138) or valve (i.e., determination step 172=“No”), the processor mayassemble the received message packets for forwarding in step 174, andtransmit those packets via the established ad hoc network in step 168.In some circumstances, the processor may also need to transmit handshakesignals to join or form such an ad hoc network in step 166. Once all ofreceived packets have been relayed via the ad hoc communication network,the processor may return to the low power sleep state in step 170.

If the processor determines the received signals are addressed to it indetermination step 172, such as an address in the message matches theserial ID stored in memory, the processor may analyze the receivedmessage to determine the type of action that is required, such as byperforming operations of method 150 that are illustrated in FIG. 16. Forexample, the processor may evaluate the received message to determinewhether it is a command to shut the valve in determination step 176. Ifso (i.e., determination step 176=“Yes”), the processor may obtain fromthe message the associated authorization code in step 178. Using theauthorization code in the message, the processor may authenticate themessage in step 180, such as by comparing the received authenticationcode to known authentication codes stored in memory (e.g., flash memory106). Other known methods for authenticating methods may be performed bythe processor as part of step 180.

If the processor determines that the shut command message is authenticin determination step 182, the processor may actuate the valve closuremechanism to move it to the close positioned in step 184. As part of thevalve closing process, the processor may set a flag bit indicating thatthe valve should be in the closed configuration in step 186. Settingsuch a flag value in memory may enable the processor to later determinewhether the valve has improperly returned to the open configuration. Avalve shut bit may also be useful in reporting status of the valve, suchas to a central server. The processor may also be configured to query asensor to sense whether the valve ball is in the shut position orconfirm that the valve ball is no longer in the open position in step188. In step 190, the processor may transmit the determine the valveposition in a reporting message to the device issuing the valve closurecommand via the wireless ad hoc communication network in step 190. Withthe valve shut operation completed, the processor may return to step 160described above with reference to FIG. 15. Also, if the processordetermines that the received shut command message was not authentic(i.e., determination step 182=“No”), the processor may be configured toignore such messages and return to step 160 described above withreference to FIG. 15.

If the processor determines that the received message is not a shutcommand (i.e., determination step 176=“No”), the processor may determinewhether the message is requesting valve status information, such as thecurrent position of the valve in determination step 192. If theprocessor determines that the message is a valve position inquiry (i.e.,determination step 192=“Yes”), the processor may query sensors to sensethe valve ball position in step 188 and report that information in step190 to the device issuing a valve position inquiry message, beforereturning to step 160 in FIG. 15.

If the received message is not a valve position inquiry (i.e.,determination step 192=“No”), the processor may determine whether thereceived message is requesting current sensor data in determination step194. If so, the processor may proceed to step 156 described above withreference to FIG. 15 even though it may not be time to report dataaccording to predefined schedule.

If the received message is not a sensor query (i.e., determination step194=“No”), the processor may determine whether the received messageprovides a valve reset command in determination step 196. If so, theprocessor may reset the valve close flag bit in memory in step 198 and,if so configured, actuate the valve closure mechanism to the openconfiguration in step 200. As described above, this may involveenergizing an actuator motor which moves an actuator gear causing anexternal magnet to move the valve ball from the close positioned to theopen configuration. Once the valve open actuation is completed, theprocessor may confirm the valve open state by sensing the valve ballposition in step 188. The processor may also transmit the valve positioninformation in step 192 the device that issued the valve reset command,before returning to step 160 in FIG. 15.

If the received message is not a valve reset command (i.e.,determination step 196=“No”), the processor may perform whatever othercommand is indicated in message. A wide variety of other functions maybe programmed into the control processor. For example, in an embodiment,a command may request the valve's relative location information, inwhich case the processor may estimate its location relative to othervalves and communication nodes in the ad hoc wireless communicationnetwork based upon their respective signal strength, and report theposition information (or relative signal strength) to the devicerequesting the position information.

While FIG. 16 illustrates a series of “if-then” determinations by whichthe processor may determine an action requested by the received message,such determinations may be determined directly by recognizing aparticular command code within the message. For example, command codesmay be in the form of a single byte of information which the processorcan compare to a table of commands in a table lookup procedure in orderto determine in one step the actions that should be taken. Other knownmessage interpretation methods may also be used for determining theappropriate course of action that should be implemented in response to areceived command message.

As mentioned above, some embodiments may include sensors that may beused to report internal and ambient conditions, such as temperature orvarious gas concentrations. Such functionality may be implemented byincluding appropriate sensor interpretation steps within the softwareinstructions programmed into the processor, such as illustrated inmethod 151 illustrated in FIG. 17. In this example method, after theprocessor has obtained sensor data in step 156, the processor mayinterpret the stored data to determine if any automatic actions arerequired. For example, in determination step 204 the processor maycompare the valve position as determined by sensors to the position itshould be in. For example, if the processor determines from sensorvalues that the valve is in the open configuration but the valve shutflag bit is set indicating that the valve should be closed (i.e.,determination step 204=“Yes”), the processor may actuate the valveclosure mechanism in step 184. As a further example, if the processordetermines that the valve is open and the shut bit is not set (i.e.,determination step 204=“No”), the processor may compare the temperaturemeasured by a temperature sensor to a maximum limit stored in memory todetermine whether the maximum threshold is exceeded in determinationstep 206. If the maximum temperature is exceeded (i.e., determinationstep 206=“Yes”), the processor may set the valve closed flag in step 186and then actuate the valve closure mechanism in step 184. Afterperforming the valve closure actuation in step 184, processor mayre-perform the sensor query operation in step 156 to confirm that thevalve is now in the closed configuration. With automatic responsescompleted, the processor may proceed with the operations described abovewith reference to FIGS. 15 and 16.

While the various embodiments have been disclosed as a standalone valveassembly, the embodiments may also be incorporated within or as part ofa gas meter or other type of fluid measurement instrument. In such aconfiguration, the valve may be included as part of the gas flow paththrough the meter, and the wireless communication and controlelectronics 10 may be integrated with or included as part of theelectronics used in the gas meter. In such embodiments, the wireless adhoc communication network enabled by the wireless communication andcontrol electronics 10 may be used to report meter readings to a centralserver 138. This embodiment would enable utilities to collect gasconsumption readings through wireless networks without the need toestablish dedicated communication networks.

Power for the wireless communication and control electronics 10 of thevarious embodiments may be provided by any known power source. In afirst embodiment, power may be provided by a convention battery 62. In asecond embodiment, power may be provided by a solar cell positioned on asurface of the valve body 2 or electronics package 3. Such a solar cellmay generate power from incandescent light shining on the valve, whichmay be used to trickle charge a rechargeable battery 62 in order toextend battery life. In a third embodiment, power may be provided by afuel cell which will have a configuration similar to that of the battery62 shown in FIG. 2. Such a fuel cell may convert a small flow of gasinto hydrogen gas and CO₂ via a catalyst, and then react the hydrogenwith oxygen from the atmosphere to generate electricity using known fuelcell configurations. The electricity from the fuel cell may power thevalve electronics, and may also be used to trickle charge a rechargeablebattery. In fourth embodiment, power from an external source, such ashouse current, other power-generating meters is used to power the valveelectronics and/or trickle charge a rechargeable battery. In a fifthembodiment, power may be harvested from the kinetic energy in the flowof fluids though the fluid line or other nearby fluid supply lines by anenergy harvesting mechanism, such as by means of a rotating turbinecoupled to an electrical generator. Energy harvesting mechanismssuitable for use in various embodiments, particularly in applicationswhere the fluid is a liquid (e.g., water) are disclosed in U.S. Pat. No.7,605,485, which is hereby incorporated by reference in its entirety.

The foregoing method descriptions and the process flow diagrams areprovided merely as illustrative examples and are not intended to requireor imply that the steps of the various embodiments must be performed inthe order presented. As will be appreciated by one of skill in the artthe order of steps in the foregoing embodiments may be performed in anyorder. Words such as “thereafter,” “then,” “next,” etc. are not intendedto limit the order of the steps; these words are simply used to guidethe reader through the description of the methods. Further, anyreference to claim elements in the singular, for example, using thearticles “a,” “an” or “the” is not to be construed as limiting theelement to the singular.

The various illustrative logical blocks, modules, circuits, andalgorithm steps described in connection with the embodiments disclosedherein may be implemented as electronic hardware, computer software, orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. Skilled artisans mayimplement the described functionality in varying ways for eachparticular application, but such implementation decisions should not beinterpreted as causing a departure from the scope of the presentinvention.

The hardware used to implement the various illustrative logics, logicalblocks, modules, and circuits described in connection with the aspectsdisclosed herein may be implemented or performed with a general purposeprocessor, a digital signal processor (DSP), an application specificintegrated circuit (ASIC), a field programmable gate array (FPGA) orother programmable logic device, discrete gate or transistor logic,discrete hardware components, or any combination thereof designed toperform the functions described herein. A general-purpose processor maybe a microprocessor, but, in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices,e.g., a combination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration. Alternatively, some steps ormethods may be performed by circuitry that is specific to a givenfunction.

In one or more exemplary aspects, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored as one or moreinstructions or code on a computer-readable medium. The steps of amethod or algorithm disclosed herein may be embodied in aprocessor-executable software module which may reside on a tangible,non-transitory computer-readable storage medium. Tangible,non-transitory computer-readable storage media may be any availablemedia that may be accessed by a computer. By way of example, and notlimitation, such, non-transitory computer-readable media may compriseRAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic diskstorage or other magnetic storage devices, or any other medium that maybe used to store desired program code in the form of instructions ordata structures and that may be accessed by a computer. Disk and disc,as used herein, includes compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and blu-ray disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Combinations of the above should also be includedwithin the scope of non-transitory computer-readable media.Additionally, the operations of a method or algorithm may reside as oneor any combination or set of codes and/or instructions on a tangible,non-transitory machine readable medium and/or computer-readable medium,which may be incorporated into a computer program product.

The preceding description of the disclosed embodiments is provided toenable any person skilled in the art to make or use the presentinvention. Various modifications to these embodiments will be readilyapparent to those skilled in the art, and the generic principles definedherein may be applied to other embodiments without departing from thespirit or scope of the invention. Thus, the present invention is notintended to be limited to the embodiments shown herein but is to beaccorded the widest scope consistent with the following claims and theprinciples and novel features disclosed herein.

What is claimed is:
 1. A fluid shutoff valve, comprising: a valveassembly comprising: a valve body having a fluid inlet, a fluid outletand a valve interior, at least a portion of the valve body comprising anon-ferromagnetic material; a valve ball positioned within the valveinterior, the valve ball comprising a ferromagnetic material; and avalve seat within the valve interior, wherein the valve ball and valveseat are configured to inhibit flow of fluid through the fluid outletwhen the valve is in a shut configuration; a valve actuation mechanismcomprising a magnet positioned outside the valve interior; a controlprocessor electrically coupled to the valve actuation mechanism; and awireless transceiver coupled to the control processor, the wirelesstransceiver being configured to communicate via a wireless communicationnetwork, wherein the control processor is configured withprocessor-executable instructions to send a valve closure signal to thevalve actuation mechanism in response to receiving a valve closurecommand message transmitted via the wireless communication network, andwherein the valve actuation mechanism is configured to: position themagnet on an exterior surface of the valve body when the valve is in theshut configuration so as to apply a magnetic field from the magnet tothe valve ball with sufficient force to hold the valve ball in aposition removed from the valve seat associated with an openconfiguration; and reduce the magnetic force applied to the valve ballsufficient to enable the valve ball to engage the valve seat in responseto receiving the valve closure signal from the control processor.
 2. Thefluid shutoff valve of claim 1, wherein the valve body is configured tocause the valve ball to move from the force of gravity to engage thevalve seat when the applied magnetic force is reduced.
 3. The fluidshutoff valve of claim 2, wherein the valve body comprises a V-shapedstructure having a wider end proximal to the valve seat and a narrow endproximal to the magnet when the valve is in the open configuration. 4.The fluid shutoff valve of claim 1, wherein the valve seat comprises aconical section positioned proximal to the fluid outlet, the conicalsection having a diameter and conic angle configured to contact thevalve ball so as to form an effective fluid seal when the valve is inthe shut configuration.
 5. The fluid shutoff valve of claim 1, whereinthe valve actuation mechanism comprises: an actuation gear coupled tothe magnet and rotatably coupled to the valve assembly; a drive gearengaged with the actuation gear; and a drive motor mechanically coupledto the drive gear and electrically coupled to the control processor,wherein the actuation gear is configured so that: when it is in a firstrotational orientation the magnet is positioned adjacent the valveassembly so as to apply a magnetic force to the valve ball sufficient tomaintain the valve ball in the position removed from the valve seatassociated with an open configuration; and when the actuation gear isrotated to a second rotational orientation by the drive motor rotatingthe drive gear the magnet is repositioned to so as to reduce themagnetic force applied to the valve ball.
 6. The fluid shutoff valve ofclaim 5, wherein the actuator gear is configured and positioned withrespect to the valve assembly so that when the actuation gear is rotatedfrom the second rotational orientation to the first rotationalorientation the magnet follows a path with respect to the valve assemblywhich applies magnetic forces to the valve ball in a manner that movesthe valve ball from the valve seat back to the position removed from thevalve seat associated with an open configuration.
 7. The fluid shutoffvalve of claim 1, wherein the valve actuation mechanism comprises anelectromagnet electrically coupled to the control processor and positionwith respect to the magnet and configured so that when energized inresponse to the valve closure signal from the control processor theelectromagnet generates a magnetic field which reduces the magneticforce applied to the valve ball.
 8. The fluid shutoff valve of claim 1,wherein the valve actuation mechanism comprises solenoid electricallycoupled to the control processor, mechanically coupled to the magnet,and configured so that when energized in response to the valve closuresignal from the control processor the solenoid causes movement of themagnet in a manner that reduces the magnetic force applied to the valveball.
 9. The fluid shutoff valve of claim 1, wherein the wirelesstransceiver and the control processor are configured to establish an adhoc wireless communication network according to one of the IEEE 802.15.4standard and the ZigBee standard.
 10. The fluid shutoff valve of claim1, further comprising one or more sensors electrically coupled to thecontrol processor, wherein the control processor is configured withprocessor-executable instructions to receive data from the one or moresensors and transmit the received sensor data via the wirelesscommunication network.
 11. The fluid shutoff valve of claim 10, furthercomprising a memory coupled to the control processor, wherein thecontrol processor is further configured with processor-executableinstructions to store data received from the one or more sensors in thememory until transmitted via the wireless communication network.
 12. Thefluid shutoff valve of claim 1, further comprising a sensor electricallycoupled to the control processor, wherein the control processor isconfigured with processor-executable instructions to perform operationscomprising: receive sensor data from the sensor; compare the receivedsensor data to a threshold value; and send the valve closure signal tothe valve actuation mechanisms when the received sensor data exceeds thethreshold value.
 13. The fluid shutoff valve of claim 1, furthercomprising a sensor electrically coupled to the control processor,wherein the control processor is configured with processor-executableinstructions to perform operations comprising: establish a wirelesscommunication network via the wireless transceiver with other fluidshutoff valves; receive sensor data from the sensor; transmit thereceived sensor data to the other fluid shutoff valves via the wirelesscommunication network; receive sensor data via the wirelesscommunication network from the other fluid shutoff valves; and send thevalve closure signal to the valve actuation mechanisms when the sensordata from other fluid shutoff valves in aggregate indicates a hazardcondition.
 14. The fluid shutoff valve of claim 1, wherein the sensor isselected from a temperature sensor, a pressure sensor, a tamperdetector, carbon monoxide sensor, and a flammable gas sensor.
 15. Thefluid shutoff valve of claim 1, further comprising: a memory coupled tothe control processor; and a valve ball position sensor coupled to thecontrol processor, wherein the control processor is configured withprocessor-executable instructions to perform operations comprising: seta valve closure status value in the memory in response to receiving thevalve closure command message; determining a position of the valve ballbased on a signal received from the valve ball position sensor; comparethe valve close status value stored in the memory to the determinedposition of the valve ball; and send the valve closure signal to thevalve actuation mechanism when the valve close status value indicatesthe valve should be in the closed configuration and the determinedposition of valve ball indicates the valve is in the open configuration.16. The fluid shutoff valve of claim 1, further comprising an electricalpower source electrically coupled to the control processor, theelectrical power source including one or more of a battery, arechargeable battery, a solar cell, a fuel cell configured to generateelectricity from a fluid flowing through the valve, energy harvestingmechanism configured to harvest kinetic energy of a fluid flowingthrough the valve, and an external power source.
 17. The fluid shutoffvalve of claim 1, wherein the valve assembly is configured as acombustible gas shutoff valve.
 18. The fluid shutoff valve of claim 1,wherein the control processor is configured with processor-executableinstructions to be reprogrammable via a wireless network established viathe wireless transceiver.
 19. A fluid flow meter, comprising: a fluidmeter configured to measure a volume of fluid passing through the meter;a shutoff valve assembly comprising: a valve body having a fluid inlet,a fluid outlet and a valve interior, at least a portion of the valvebody comprising a non-ferromagnetic material; a valve ball positionedwithin the valve interior, the valve ball comprising a ferromagneticmaterial; and a valve seat within the valve interior, wherein the valveball and valve seat are configured to inhibit flow of fluid through thefluid outlet when the valve is in a shut configuration; a valveactuation mechanism comprising a magnet positioned outside the valveinterior; a control processor electrically coupled to the valveactuation mechanism and to the fluid meter; and a wireless transceivercoupled to the control processor, the wireless transceiver beingconfigured to communicate via a wireless communication network, whereinthe control processor is configured with processor-executableinstructions to comprising: sending a valve closure signal to the valveactuation mechanism in response to receiving a valve closure commandmessage transmitted via the wireless communication network; andreceiving meter data from the fluid meter and transmitting the meterdata via the wireless communication network; and wherein the valveactuation mechanism is configured to: position the magnet on an exteriorsurface of the valve body when the valve is in the shut configuration soas to apply a magnetic field from the magnet to the valve ball withsufficient force to hold the valve ball in a position removed from thevalve seat associated with an open configuration; and reduce themagnetic force applied to the valve ball sufficient to enable the valveball to engage the valve seat in response to receiving the valve closuresignal from the control processor.
 20. A method of closing a fluidshutoff valve, comprising: establishing a communication link with awireless communication network via a wireless transceiver within thefluid shutoff valve; receiving in a control processor of the fluidshutoff valve a valve closure command message from the wirelesscommunication network; sending a valve closure signal from the controlprocessor to a valve actuation mechanism within the fluid shutoff valvein response to receiving the valve closure command message; reducing amagnetic force that is maintaining a valve ball within the fluid shutoffvalve in an open configuration sufficient to enable the valve ball tomove to a closed configuration; storing in a memory a valve close statusvalue in response to receiving the valve closure command message;sensing a position of the valve ball within the fluid shutoff valve; andsending a valve closure signal from the control processor to the valveactuation mechanism within the fluid shutoff valve when the valve closestatus value stored in memory indicates that the fluid shutoff valveshould be in a closed configuration but the sensed position of the valveball indicates the fluid shutoff valve is in an open configuration. 21.The method of claim 20, further comprising: receiving in the controlprocessor sensor data from a sensor coupled to the fluid shutoff valve;comparing the received sensor data to a threshold value; and sending avalve closure signal from the control processor to the valve actuationmechanism within the fluid shutoff valve when the received sensor dataexceeds the threshold value.
 22. The method of claim 20, furthercomprising: receiving in the control processor sensor data from a sensorcoupled to the fluid shutoff valve; and transmitting the received sensordata via the wireless communication network.
 23. The method of claim 22,further comprising storing data received from the one or more sensors ina memory until transmitted via the wireless communication network. 24.The method of claim 20, further comprising: receiving in the controlprocessor sensor data from a sensor not associated with the fluidshutoff valve; and transmitting the received sensor data via thewireless communication network.
 25. The method of claim 20, furthercomprising: formulating a valve closure command message including anidentifier of the fluid shutoff valve within a central server; andtransmitting the valve closure command message from the central serverto the fluid shutoff valve via a wired network to a gateway node that ispart of the wireless communication network, wherein receiving in thecontrol processor of the fluid shutoff valve a valve closure commandmessage from the wireless communication network comprises: receiving thevalve closure command message from the wireless communication network;obtaining the identifier from within the valve closure command message;comparing the obtained identifier to an identifier known to the controlprocessor; and ignoring the valve closure command message if theobtained identifier does not compare favorably to the identifier knownto the control processor.
 26. The method of claim 20, furthercomprising: establishing a communication link with the wirelesscommunication network from a wireless communication device; formulatingin the wireless communication device a valve closure command messageincluding an identifier of the fluid shutoff valve; and transmittingfrom the wireless communication device to the fluid shutoff valve viathe wireless communication network, wherein receiving in the controlprocessor of the fluid shutoff valve a valve closure command messagefrom the wireless communication network comprises: receiving the valveclosure command message from the wireless communication network;obtaining the identifier from within the valve closure command message;comparing the obtained identifier to an identifier known to the controlprocessor; and ignoring the valve closure command message if theobtained identifier does not compare favorably to the identifier knownto the control processor.
 27. A method of closing a fluid shutoff valve,comprising: establishing a communication link with a wirelesscommunication network via a wireless transceiver within the fluidshutoff valve; receiving in a control processor of the fluid shutoffvalve a valve closure command message from the wireless communicationnetwork; sending a valve closure signal from the control processor to avalve actuation mechanism within the fluid shutoff valve in response toreceiving the valve closure command message; reducing a magnetic forcethat is maintaining a valve ball within the fluid shutoff valve in anopen configuration sufficient to enable the valve ball to move to aclosed configuration; receiving signals from a plurality ofcommunication nodes within the wireless communication network; measuringsignal strengths of the signals received from the plurality ofcommunication nodes; estimating a distance to each of the plurality ofcommunication nodes based upon the measured signal strengths; estimatinga position of the fluid shutoff valve with respect to the plurality ofcommunication nodes; reporting the estimated position of the fluidshutoff valve via the wireless communication network.